Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Paper Brain Behav Evol 2006;67:150–164 DOI: 10.1159/000090979 Distribution of Neuropeptide FF-Like Immunoreactivity in the Brain of Dermophis mexicanus (Amphibia; Gymnophiona): Comparison with FMRFamide Immunoreactivity Jesús M. López Nerea Moreno Ruth Morona Agustín González Departamento de Biología Celular, Facultad de Biología, Universidad Complutense, Madrid, Spain features were present in the gymnophionan such as the lack of NPFF-ir cells in the telencephalon, brainstem and spinal cord and the absence of NPFF-ir fibers in the hy- pophysis and the olfactory bulbs. This pattern was dis- tinct from that observed for FMRFamide distribution. Striking differences were noted in the pallium, caudal hypothalamus and midbrain tegmentum where FMRF- amide – containing cells were localized. The present results in Dermophis support the idea that data from gymnophionans must be included when stating the am- phibian condition of a given system because important variations are obvious when gymnophionans are com- pared with anurans and urodeles. Copyright © 2006 S. Karger AG, Basel Introduction The neuropeptide FF (NPFF) is an FMRF-NH 2 -like octapeptide first isolated from bovine brain [Yang et al., 1985] and distinct from the molluscan tetrapeptide FMRFamide [Price and Greenberg, 1977; Majane et al., 1989; Lee et al., 1993]. Several studies have demonstrat- ed that NPFF is present in neurons and fibers in numer- ous places in the mammalian brain. Characteristically, NPFF immunoreactive (NPFF-ir) cell bodies were found in a few locations within the brain and spinal cord, where- Key Words Neuropeptide FF  FMRFamide peptides  Immunohistochemistry  Comparative neuroanatomy  Evolution  Amphibian Abstract Neuropeptide FF (NPFF) is an FMRFamide-related pep- tide widely distributed in the mammalian brain. NPFF immunohistochemistry labeled cell bodies in a few loca- tions and dense fiber networks throughout the brain. Re- cently, the distribution of NPFF immunoreactive (NPFF- ir) cells and fibers in the brain of anuran and urodele amphibians was studied and, as in mammals, significant species differences were noted. To further assess gen- eral and derived features of the NPFF-containing neuron system in amphibians, we have investigated the distribu- tion of NPFF-ir cell bodies and fibers in the brain of the gymnophionan Dermophis mexicanus by means of an antiserum against bovine NPFF. This distribution was compared to that of FMRFamide immunoreactivity. Ma- jor traits shared with anurans and urodeles were the abundant fiber labeling in the ventral telencephalon, hy- pothalamus, isthmus, ventrolateral medulla and dorsal spinal cord. In addition, in the three amphibian orders the majority of the NPFF-ir cells were located in the pre- optic-hypothalamic region. However, distinct particular Received: July 21, 2005 Returned for revision: September 26, 2005 Accepted after revision: September 29, 2005 Published online: January 13, 2006 Dr. Agustín González Department of Cell Biology, Faculty of Biology University Complutense ES–28040 Madrid (Spain) Tel. +34 91 394 4977, Fax +34 91 394 4981, E-Mail agustin@bio.ucm.es © 2006 S. Karger AG, Basel 0006–8977/06/0673–0150$23.50/0 Accessible online at: www.karger.com/bbe